scholarly journals Paenidigyamycin A, Potent Antiparasitic Imidazole Alkaloid from the Ghanaian Paenibacillus sp. DE2SH

Marine Drugs ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 9 ◽  
Author(s):  
Enoch Osei ◽  
Samuel Kwain ◽  
Gilbert Mawuli ◽  
Abraham Anang ◽  
Kofi Owusu ◽  
...  

A new alkaloid paenidigyamycin A (1) was obtained from the novel Ghanaian Paenibacillus sp. isolated from the mangrove rhizosphere soils of the Pterocarpus santalinoides tree growing in the wetlands of the Digya National Park, Ghana. Compound 1 was isolated on HPLC at tR = 37.0 min and its structure determined by MS, 1D, and 2D-NMR data. When tested against L. major, 1 (IC50 0.75 µM) was just as effective as amphotericin B (IC50 0.31 µM). Against L. donovani, 1 (IC50 7.02 µM) was twenty-two times less active than amphotericin B (IC50 0.32 µM), reinforcing the unique effectiveness of 1 against L. major. For T. brucei brucei, 1 (IC50 0.78 µM) was ten times more active than the laboratory standard Coptis japonica (IC50 8.20 µM). The IC50 of 9.08 µM for 1 against P. falciparum 3d7 compared to artesunate (IC50 36 nM) was not strong, but this result suggests the possibility of using the paenidigyamycin scaffold for the development of potent antimalarial drugs. Against cercariae, 1 showed high anticercaricidal activity compared to artesunate. The minimal lethal concentration (MLC) and minimal effective concentration (MEC) of the compound were 25 and 6.25 µM, respectively, while artesunate was needed in higher quantities to produce such results. However, 1 (IC50 > 100 µM) was not active against T. mobilensis.

Molbank ◽  
10.3390/m1080 ◽  
2019 ◽  
Vol 2019 (3) ◽  
pp. M1080 ◽  
Author(s):  
Samuel Kwain ◽  
Gilbert Tetevi ◽  
Thomas Mensah ◽  
Anil Camas ◽  
Mustafa Camas ◽  
...  

Digyaindoleacid A (1) is one of the novel alkaloids produced by the Ghanaian Paenibacillus sp. DE2SH (GenBank Accession Number: MH091697) isolated from the mangrove rhizosphere soils of the Pterocarpus santalinoides tree growing in the wetlands of the Digya National Park, Brong Ahafo Region, Ghana. This compound was isolated on HPLC at tR ≈ 60 min and its structure determined by MS, 1D, and 2D-NMR data. When tested against Trypanosoma brucei subsp. brucei strain GUTat 3.1, 1 produced a half-maximal inhibitory concentration (IC50) 5.21 μM compared to the standard diminazene aceturate (IC50 = 1.86 μM). In the presence of normal mouse macrophages RAW 264.7, 1 displayed a higher selectivity towards T. brucei subsp. brucei (selectivity indices (SI) = 30.2) with low toxicity. This result is interesting given that the drug diminazene aceturate is considerably toxic and 1 is a natural product isolate. The structure of 1 incorporates the backbone of the amino acid tryptophan which is crucial in the metabolism of Trypanosoma brucei subsp. brucei strain GUTat 3.1. It is possible that 1, could interfere with the normal uptake and metabolism of tryptophan in the parasite. However, 1 (IC50 = 135.41 μM) produced weak antileishmanial activity when tested against Leishmania donovani (Laveran and Mesnil) Ross (D10).


2002 ◽  
Vol 57 (1) ◽  
pp. 25-42 ◽  
Author(s):  
Peter Rutsch ◽  
Gottfried Huttner

The disodium salt Na2[{(CO)5Cr}2Pb(NO3)2], Na2·1, which contains a lead center in a (4+2) coordination mode, reacts with tetraphenylphosphonium halides [Ph4P]X to give the tetrahedral compounds [Ph4P]2[{(CO)5Cr}2PbX2] (X = Cl: 2a; X = Br: 2b; X = I: 2c). Substitution of the nitrate groups of Na2·1 by alcoxides leads to binuclear compounds of the type [{(CO)5Crg2Pb(μ2-OR)2Pb{Cr(CO)5}2]2- (R = Et: 3a; R = n -Pr: 3b; R = i-Pr: 3c; R = Allyl: 3d). NMR experiments show that these dimeric compounds are in equilibrium with the monomeric species [{(CO)5Cr}2PbR]- .Trialkylphosphanes react with Na2·1 to give the neutral phosphane complexes [{(CO)5Cr}2Pb(PR3)2] (R=Me: 4a; R=Et: 4b; R = n-Bu: 4c), which show dynamic behaviour in solution. All of the novel compounds have been characterized by X-ray analysis, as well as by the usual analytic and spectroscopic techniques. 207Pb-NMR data of Cr(CO)5- bound lead species are reported for the first time.


1989 ◽  
Vol 111 (4) ◽  
pp. 1484-1491 ◽  
Author(s):  
Thomas G. Pagano ◽  
Paulos G. Yohannes ◽  
Benjamin P. Hay ◽  
Jerry R. Scott ◽  
Richard G. Finke ◽  
...  

2020 ◽  
Vol 16 ◽  
pp. 3078-3085
Author(s):  
Joon Min Cha ◽  
Dong Hyun Kim ◽  
Lalita Subedi ◽  
Zahra Khan ◽  
Sang Un Choi ◽  
...  

A new megastigmane-type norsesquiterpenoid glycoside, chaemeloside (1), was isolated from the twigs of Chaenomeles sinensis together with 11 known phytochemicals through chromatographic methods. The chemical structure of the new isolate 1 was determined by conventional 1D and 2D NMR data analysis, ECD experiment, hydrolysis followed by a modified Mosher’s method, and LC–MS analysis. The characterized compounds’ biological effects including cytotoxicity against cancer cell lines, antineuroinflammatory activity, and potential neurotrophic effect were evaluated.


Author(s):  
Byeonung-Kyu Choi ◽  
Shin-Young Park ◽  
Song-Hee Jo ◽  
Dong-Kug Choi ◽  
Phan Thi Hoai Trinh ◽  
...  

A new compound containing a triene, a tetrahydropyran ring and glycine ester functionalities, restricticin B (1), together with four known compounds (2-5) were obtained from the EtOAc extract of the marine fungus Penicillium janthinellum. The planar structure of 1 was determined by detailed analyses of MS, 1D and 2D NMR data. The relative and absolute configurations of 1 were established via analyses of NOESY spectroscopy data, comparison of optical rotation values with those of restricticin derivatives reported and electronic circular dichroism (ECD). All the compounds were screened for their anti-neuroinflammatory effects in lipopolysaccharide (LPS)-induced BV-2 microglia cells. Restricticin B (1) and N-acetyl restricticin (2) exhibited anti-neuroinflammatory effects by suppressing the production of pro-inflammatory mediators in activated microglial cells.


2013 ◽  
Vol 13 (3) ◽  
pp. 216-220 ◽  
Author(s):  
Anggia Murni ◽  
Novriyandi Hanif ◽  
Junichi Tanaka

One new dolabellane (1) and two known diterpenoids stolonidiol (2) and clavinflol B (3) have been isolated from the ethyl acetate extract of the Indonesian soft coral Anthelia sp. A new compound 1 exhibited a moderate cytotoxicity against NBT-T2 cells at 10 µg/mL, while known compounds 2 and 3 showed cytotoxicity at 1 and 0.5 µg/mL, respectively. Structure of the new compound 1 was elucidated by interpretation of NMR spectroscopic data (1D and 2D NMR data) and mass spectrometry (ESIMS data) as well as comparison with those of related ones. This finding should be useful for anti cancer drug development of the promising dolabellane-types compound.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Jeffrey Jenkins ◽  
Felber Arroyave ◽  
Madeline Brown ◽  
Jullianna Chavez ◽  
Johnny Ly ◽  
...  

Yosemite National Park is a popular tourist destination with high visitation levels that have increased throughout the summer season over the past several decades. Like with other protected areas, high visitation levels pose challenges for coordinating resources, infrastructural capacity, and visitor experiences. Use limits, including rationing vehicle entry at gates by reservation, are one possible strategy to manage visitation levels. After an initial full closure, the park chose to operationalize a multiphased permit system for day-use and overnight entry over the course of the pandemic in accordance with local and national guidelines for operational safety. While park closures and other entry restrictions have been common in recent years due to wildland fires and other natural hazards, the pandemic-related entry limits represent a nearly yearlong experiment. The prolonged entry ration along with restrictions to group activities has limited visitation and potentially reduced transmission of the novel coronavirus. We review the per capita COVID-19 case count in surrounding counties given the flow of tourism from outside the region, assess the changes in access to the park with the novel reservation system, compare monthly visitation during the 2020 use limits with prior decadal averages, detail how high visitation levels and crowding persist, and review the Park’s plans for an ongoing day-use permit system. We conclude with the ongoing challenges managers face in light of continued high visitation. Readers will be able to debate the efficacy of use limits and what may be a sustainable level of visitation for the park.


2000 ◽  
Vol 7 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Yangzhong Liu ◽  
Maria F. Sivo ◽  
Giovanni Natile ◽  
Einar Sletten

Recently it has been shown that several analogues of the clinically ineffective trans-DDP exhibit antitumor activity comparable to that of cis-DDP. The present paper describes the binding of antitumor trans-[PtCl2(E-iminoether)2] (trans-EE) to guanosinemonophosphate (GMP) and adenosinemonophosphate (AMP). We have used HPLC and H1 and N15 NMR to characterize the different adducts. In the case of a 1:1 mixture of trans-EE and GMP, at an early stage of the reaction, a monofunctional adduct is formed which, subsequently, is partly converted into a monosolvated monofunctional species. After about 70 hours an equilibrium is established between chloro and solvato monofunctional adducts at a ratio of 30/70. In the presence of excess GMP (4:1) the initially formed monofunctional adducts react further to give two bifunctional adducts, one with the iminoether ligands in their original E configurations and the other with the iminoether ligands having one E and the other, Z configurations. The coordination geometry obtained by energy minimization calculations is in qualitative agreement with 2D NMR data.


Sign in / Sign up

Export Citation Format

Share Document